Designing Reliable Virtualized Radio Access Networks

TL;DR

This paper develops an analytical model to evaluate how virtualization and disaggregation affect the availability of Radio Access Networks, highlighting the importance of container platform reliability and replication strategies.

Contribution

It introduces a Markov chain-based model to analyze RAN resiliency, providing insights into the effects of hardware/software disaggregation and replication on network availability.

Findings

Container platform reliability limits vRAN availability

Increasing hardware replication beyond 2 offers limited benefits

Distributed CUs may enhance reliability compared to centralized ones

Abstract

As virtualization of Radio Access Networks (RAN) gains momentum, understanding the impact of hardware and software disaggregation on resiliency becomes critical to meet the high availability requirements of mobile networks. Our paper presents an analytical model, using continuous time Markov chains, to study the impact of virtualization and disaggregation on RAN availability. Our evaluation, assuming typical parameter value ranges for failure and recovery rates, points to containerized platform reliability as a constraint on vRAN availability. We also find that with active-passive replication, increasing hardware replication factor beyond 2 may not bring any benefits unless failover times are reduced. We also compare the reliability of centralized and distributed virtualized central units.